Drone attack destroys 16 trucks carrying UN food to Sudan’s famine-hit Darfur region

>Gross said it was not yet clear who was responsibility for Wednesday’s attack, the second in the past three months to prevent a U.N. convoy from delivering to North Dafur. In early June, a convoy from the World Food Program and UNICEF was attacked while awaiting clearance to proceed to North Darfur’s besieged capital, el-Fasher, killing five people and injuring several others.

Who was responsible for the first attack before this one?

Also who would have a motivation to do so?